Bristol Heat Network

Where and how

Existing Networks and proposed expansions

In 2019 Bristol City Council commissioned ‘Bristol net zero by 2030: The evidence base’ by the Centre for Sustainable Energy. This report indicated a heat network potentially delivering zero carbon heat to up to 62,000 residential buildings and 6,000 commercial buildings in the city. This could see the delivery of up to 3TWh of zero carbon heat annually through up to 1,000 km of heat networks.

In response to this the council has focused on developing heat networks in high heat demand areas such as central Bristol and the Bristol Heat Network was created! Now live in Redcliffe and Old Market, supplying heat for space heating and hot water to many buildings, businesses and residents. The network is now being extended to Bedminster and the Temple area, with possible routes to connect these areas together being explored. Feasibility studies have also been carried out into further network areas in Ashton Gate, City Centre, Frome Gateway and Spike Island and these will be commenced in the coming years.

Bristol now has England’s largest water source heat pump at Castle Park. This facility is providing efficiently generated heat using renewable electricity to extract heat from the floating harbor before pumping it via buried network to nearby homes and businesses. As the network grows it will be increasingly reliant on low-carbon sources of heat.

Why were these areas chosen?

The way that heat network business models tend to work is that in order to make them commercially viable, they often need to be built in areas where there is a guarantee of a large heat demand and this is best achieved by ensuring (through the planning process) that new developments are required to connect to the network.

This brings in revenue from connection fees and ongoing heat and service charges that ensure the network can continue to run.

Local authorities generally don’t have the money to invest in multi-million pound heat network projects on their own so they put together a business plan and commercial model for a network area (such as the new network in Bedminster) which demonstrates that there will be a demand for the heat (often from new developments) and apply for grant funding from central government. In areas where there is a large amount of development taking place the viability of a network can more easily be demonstrated and grant funding can be sought to get it off the ground.

What this means is that the focus of the network’s activity for the next few years will have to be on connecting up these larger developments. These developments aren’t always popular with residents but they do have some benefits to the area – one of which is enabling the construction of the heat network which will eventually serve many of the other residents.

The benefits of connecting to heat networks in Bristol

Benefits for developers and building owners and operators

• Lower capital and operational costs. Connection to a heat network is simpler than installing boiler plant equipment in individual buildings as these are replaced by a single heat substation. This means procurement, capital, operational, maintenance and replacement costs are lower than conventional heating solutions.
• Space saving. Heat substations require a much smaller footprint than conventional gas boilers, increasing the lettable/saleable floor area of developments.
• Oversizing. Because the heat network can adjust the temperature/volume of heat delivered to match exceptional periods of cold weather, it’s no longer necessary to oversize heating systems, meaning they are cheaper to install and maintain and operate more efficiently.
• Secure. In a volatile energy market, district heat can provide energy security and resilience through the utilisation of a variety of heat generation sources, long-term contracts and price guarantees. Unlike systems supplied by fossil fuels.
• Future-proof. Bristol City Council is making the transition to renewable and low carbon district heat so you won’t be tied into stranded technologies or fuels such as fossil fuels.
• Compliance with Building Regulations and Bristol City Council Planning Policies, BCS13 and 14. Connection to district heat can make it easier to meet the requirements of Parts L1A and 2A of the Building Regulations and is a requirement of Bristol City Council’s policy BCS14 for development in areas of the city where district heating is planned or in construction. Measures such as direct electric resistive heating do not meet the requirements of planning policy BCS14.
• Improved air quality – Our heat networks are designed in accordance with industry best practice, and reduce local air pollution when compared to multiple gas boilers.
• Carbon reduction – Connection to heat networks is a very cost-efficient way of reducing carbon emissions from existing buildings undergoing major refurbishment and replacement of heating systems, particularly those which are ‘hard to treat’, such as listed buildings or those with solid walls.

Benefits for consumers of heat connected to heat networks

• Reduced energy costs – Bristol City Council is committed to lowering the cost of energy by providing heat via heat networks. Greater efficiency of heat networks over individual gas boilers enables the council to deliver heat via its heat network at a cost lower than that of an equivalent gas boiler system and significantly lower than direct (resistive) electric heating.
• Greater resilience to volatile energy prices
  • By lowering the cost of energy and reducing volatility the council can assist business and domestic consumers.
  • Low cost heat helps to reduce the proportion of household income spent on energy and the incidence of fuel poverty.
• Space saving – Heat interface units (HIUs)2 require less space than a conventional gas boiler and hot water tank or a combination boiler.
• Simple, clear tariffs – Bristol City Council is committed to simple, clear tariffs which will typically be based on a standing charge and a heat charge based on metered heat consumption.